New Study Links Menopause To Brain Changes, Higher Dementia Risk

A major new UK study, published in the journal Psychological Medicine and funded by the Wellcome Trust with support from the National Institute for Health and Care Research, has found strong links between menopause, poorer mental health and changes in the brain associated with Alzheimer’s disease.

The research involved almost 125,000 women and was led by experts at the University of Cambridge. Scientists say the findings could help explain why women are more likely than men to develop dementia later in life.

Menopause linked to brain changes

Menopause is a natural stage in a woman’s life when periods stop due to falling hormone levels. It usually occurs between the ages of 45 and 55 and is already known to cause symptoms such as hot flushes, sleep problems, and low mood. This new research suggests it may also be a critical period for brain health.

The study found that women who had gone through menopause showed a reduction in grey matter in the brain. Grey matter is essential for memory, thinking, emotions, and movement. Loss of grey matter is also a key feature of Alzheimer’s disease.

Around 11,000 women in the study underwent MRI brain scans. These scans showed that post menopausal women had lower grey matter volume compared with women who had not yet reached menopause.

The changes were most noticeable in the hippocampus, which plays a central role in learning and memory. Differences were also found in the entorhinal cortex, which helps form and store memories and supports spatial awareness. Another affected area was the anterior cingulate cortex, which is involved in attention, decision-making, and emotional control.

Professor Barbara Sahakian, the study’s senior author, said these brain regions are among the first to be affected by Alzheimer’s disease. She said menopause may increase vulnerability later in life and could partly explain why nearly twice as many women as men develop dementia.

Women make up around two-thirds of people living with Alzheimer’s disease in the UK, according to Alzheimer’s Society.

The study also examined mental health, sleep, and cognition. Researchers found that post menopausal women were more likely to report anxiety, depression, and sleep disturbances. Many said they experienced insomnia, slept less overall and felt more tired during the day.

Notably, women using hormone replacement therapy or HRT reported feeling the most tired, even though they slept for similar lengths of time as women not on HRT. All post menopausal women reported more fatigue than women who had not yet gone through menopause.

Menopause also appeared to affect thinking speed. Women who were post menopausal and not using HRT had slower reaction times than women who were pre menopausal or using HRT. However, there were no significant differences between the groups when it came to memory test performance.

Dr Katharina Zühlsdorff from the University of Cambridge said slower reaction times are a normal part of ageing for both men and women. She explained that menopause seems to speed up this process. HRT appeared to slow it slightly, but did not stop it completely.

The researchers found that HRT did not prevent the loss of grey matter in the brain. Women taking HRT were more likely to report anxiety and depression. However, further analysis showed many already had poorer mental health before starting treatment. This suggests HRT may have been prescribed because symptoms were expected to worsen during menopause.

Experts have stressed that the study does not prove menopause causes dementia. The research did not follow women over time to see whether those brain changes later led to Alzheimer’s or other forms of dementia.

Michelle Dyson, chief executive of Alzheimer’s Society, said the findings add to growing evidence that menopause affects the brain in real physical ways. She said long-term studies are still needed to understand whether these changes directly increase dementia risk.

Researchers say the findings highlight menopause as an important period for both physical and mental health. They encourage women to seek help if they are struggling and not to dismiss symptoms as normal ageing or stress.

Health experts also stress that lifestyle choices can help reduce dementia risk. Regular exercise, not smoking, limiting alcohol intake, and staying mentally and socially active are all known to support long-term brain health.